The purpose of this grant proposal is to develop an audio computer-assisted self-interviewing (audio-CASI) software package for assessing the social information processing in children. Research over the past 20 years has established a consistent relationship between social information processing (SIP) skill deficits and aggressive behavior in youth. In addition, the majority of current evidence-based programs designed to prevent or treat aggressive behavior in children or adolescents are predicated on the SIP model (Crick & Dodge, 1994) and include social cognitive intervention techniques. Despite these advances in the study of aggression, there currently exist no standardized, normed measures of SIP skills with known psychometric properties. Thus, mental health professionals and researchers do not have access to state-of-the-art measures to assess the effectiveness of their interventions or to establish treatment goals related to social cognitive functioning. The current proposal is designed to begin to fill these gaps by creating professional quality software and video clips to assess multiple stages of social information processing in children. Phase I includes two basic sets of aims regarding product development and then product testing. The product development aims include creating vignette scripts of common misunderstandings among 2nd-to 5th-grade boys; creating professional quality, digital video clips of social situations containing ambiguous intent with 2nd-5th grade male actors; designing assessment questions to reliably and validly assess multiple aspects of social information processing; creating software for audio computer-assisted self-interviewing administration; creating scoring algorithms for the SIP measures; writing clinical report shells that will summarize assessment findings and provide clinical implications for responses to the software; and developing attractive, user-friendly, developmentally and culturally appropriate computer software that incorporates video vignettes, assessment items, scoring algorithms and reporting components to assess SIP in elementary school-aged boys. The product testing aims include piloting video clips and audio-CASI software with youth to determine appropriateness, clarity, interest, and effectiveness; and to conduct quantitative analyses on a small sample of pilot data.